We are proposing a multi-year conference grant which seeks to establish a forum for researchers to pursue collaborative studies of pediatric bipolar disorder. This application was conceived in response to a recent roundtable discussion convened by the NIMH's Director, Dr. Steve Hyman, in collaboration with the Developmental Psychopathology and Prevention Research Branch and the Child and Adolescent Treatment and Preventive Intervention Research Branch. Despite controversy, the notion that pediatric bipolar disorder is exceedingly rare has been challenged by case reports and emerging research findings that suggest that this disorder may not be rare but, rather, that it is difficult to diagnose. It is also quite clear that, despite debate over nosological issues, many clinicians recognize that a sizable number of children suffer from a severe form of psychopathology associated with extreme irritability, violence, and incapacitation that is highly suggestive of bipolar disorder. Since a sizable clinical population currently exists for which relatively little systematic information is available, efforts that increase the pace and utility of research are desperately needed. Thus, an appropriate mechanism designed to facilitate regular communication among investigators and clinicians is needed as a first step to build collaborative research and guide clinical efforts that will foster a more efficient and streamlined approach to the understanding and treatment of this perplexing disorder. The main aim of the proposed conference grant is to overcome the hurdles to collaboration by establishing yearly conferences among investigators studying pediatric bipolar disorder. Subgoals of these conferences are: (1) to define the boundaries of the bipolar spectrum phenotype and determine if children who technically meet criteria for bipolar disorder actually have this disorder or are affected with another condition.; (2) to standardize data collection methods across different centers to facilitate pooling of diagnostic data and validation of the disorder; (3) to facilitate joint submissions of large collaborative projects that will enable the study of a broad spectrum of scientific questions including genetic, imaging and therapeutic protocols; and (4) to create a mechanism for pooling samples so that potential findings from one group may be cross-validated on pooled data from other groups. Although scientific projects studying pediatric bipolar disorder are likely to be funded in the coming years, these efforts will likely take many years to unfold. This scientific void and ongoing diagnostic and therapeutic uncertainties calls for immediate action to foster contact and dialogue among interested parties in the clinical and scientific community. While the field faces a dearth of information, more and more children and families are being referred to clinics for evaluation and treatment. Thus, steps that increase the identification of children with bipolar spectrum disorder and the development of initial therapeutic approaches to help them is of high clinical, scientific and public health importance. While the proposed conference does not intend to solve all outstanding problems associated with pediatric bipolar disorder, it will provide a forum to begin formulating a solution.